Well, the name is tentative, but it's growing on me. The day I began construction, I spent an hour trying to rescue a neighbors rooster. Well, it turns out it wasn't the neighbors rooster.

I'm going against the grain and building this observatory well within a red zone. Being close to home, I should get a lot of time with it and won't be worried about remote access. OF course, I'll still be dealing with LP, but I do plan on going CCD and NB before long.

It will also give me a nice view of the Sun throughout the day. So it qwill make a great solar observatory as well.

The first problem was that my entire property is on bedrock. For the low-side footers and pier, I only have 6-12" before hitting it. This means I've been drilling 5/8" holes for rebar. I've been using a hammer drill and it is tedious.

So far I have about 20" of 75" done. This took about 2 hrs of drilling. I'm considering renting a rotary hammer, but we'll see. Depends on how tomorrow goes.

I have a mason who will do the pour for me. I just have to get all of my holes dug and forms set. Hopefully, I'm only about two weeks off.

I'm curious why you're considering the wood support for the floor on one side, while concrete on the other "tall" sides; rather than concrete for all the supports? Not that it matters, I'm just wondering.

I'm curious why you're considering the wood support for the floor on one side, while concrete on the other "tall" sides?

If you look at the first picture, the entire area is sloped to the left. The entrance to the observatory will be off the driveway. The tall concrete supports actually drop into the ground within the retaining wall and drop to below the frostline. There will be backfill around them and the retaining wall will be rebult after the pour.

From what I've read, you would want the sonotube forms to finish 12" above grade. The tall concrete footers achieve this.

Yes. Big, hard rocks. And there is something about 5" down that takes forever to drill. I don't know if the bedrock just gets harder as you drill, but the last inch goes very slowly.

I bit the bullet and purchased a rotary hammer. It was $69.99 at Harbor Freight. I could've rented a better one for about the same price, but then I'd only have a day with it. As it is, I'm getting the work done when I can. I cannot wait to give the new tool a try when the rain stops.

I also picked up some 6 Simpson Strong-Tie 6x6 post bases and ordered my anchor bolts.

I also ordered the Dan's Pier Plate Bolts and will also order the 12" pier plate. I'm wondering if the 12" pier means I will have more of a clearance issue, when going past the meridian. I think that's a possibility. Hopefully, any software I use will fix that with an auto meridian flip.

I couldn't help it and I went outside last night to give the new tool a try. It works very well. The holes should go quickly and since it's so easy, I may build my rebar form for the pier coming out of the bedrock. It will help me keep it clean looking and level.

I actually saw a picture of someone pouring a pier and his rebar looked like a piece of art. Perfectly spaced and welded. I don't know if it matters, but mine is pretty ugly.

I am also SERIOUSLY STRUGGLING determining my desired PIER HEIGHT! I'm all over the place from 36" to 50". I'm a 99% imager, but would love to be able to look through a piggybacked solar scope without a ladder. What are some average pier heights?

I actually saw a picture of someone pouring a pier and his rebar looked like a piece of art. Perfectly spaced and welded. I don't know if it matters, but mine is pretty ugly.

The average amateur astro pier is built with enough rebar and concrete in it to anchor one end of the golden gate bridge, so don't be worried....a couple hunks will do you fine! The only thing important is to be sure the rebar is an inch minimum from the outside surface of the concrete. Other than that, bent scraps you found along the roadside will work just as good as perfect artwork measured to the thousandth of an inch...... one piece of 1/2" rebar in an 8" diameter post will make it strong enough that you can't break the top off with a backhoe (I know this because I've tried....) so anything beyond that, you're pretty darn safe.....
Russ

I actually saw a picture of someone pouring a pier and his rebar looked like a piece of art. Perfectly spaced and welded. I don't know if it matters, but mine is pretty ugly.

I am also SERIOUSLY STRUGGLING determining my desired PIER HEIGHT! I'm all over the place from 36" to 50". I'm a 99% imager, but would love to be able to look through a piggybacked solar scope without a ladder. What are some average pier heights?

LOL, who is ever going to bust the concreet open and say "Hmm...that rebar could have looked better".

After conversing with the mason, he is going to use thicker rebar and clean it up a bit. He doesn't think we are going to be able to do the base and pier in one pour due to the height of the pier. Hopefully this won't matter much. It will make the job a lot easier.

Now, I only have to confirm my footings and set the sonotube heights. Then comes the concrete.

I'm going to order a 12" Dans Pier Plate and the lumber as soon as the pour is done.

For pier height - start with the main scope OTA. Be sure the view through this scope will clear the wall of your obs when it is pointed up at about a 30-degree angle. The angle is really whatever you are comfortable with based on how you observe - do you ever look for targets less than 30 degrees above the horizon? If so, adjust that angle to your preference. This will tell you where the bottom of the OTA is in relation to your obs wall. Measure the distance to the floor, subtract the height of your mount and pier top plate, and the result is your desired pier height relative to your floor and obs wall.

The figures you determine above will also tell you the top height of the OTA.

Next determine the height of the piggy back mount and add half the aperture of your solar scope to that height. Add all that to the top of your OTA and you get the location of the eyepiece for the solar scope, with a diagonal turned sideways. If you view the sun early or late near the horizon be sure your view still clears the obs wall based on the characteristics of your mount.

Is this a height at which you can comfortably view? If yes, you are good to pour the pier.

You get the idea. Play around with it - draw some simple diagrams that include you and you will get comfortable.

And you can always pour a little short and try it out. You can put couplers on the mounting bolts later and extend them upward and add more concrete - or have a short steel pier made to your spec.

Well, I'm back and forth. Normally, I'd just say go higher, who cares if I can see through the tube. But I'm thinking of setting it around 38" with the pier plate.

This should clear the walls and the horizon, which isn't as generous as I'd like. I think my polar alignment scope will have most of it's field visible, but not all. I'm trying not to concern myself with that as I'll probably only use it once.

So the weather is calling for rain on Saturday. I hope this doesn't delay my project.

I'm kind of partial to topping off the cement pier with a metal pier, that way you can make it shorter or longer pretty easily ..also it will give you more clearance for your tube if your mount is a GEM when near the meridian

I'm kind of partial to topping off the cement pier with a metal pier, that way you can make it shorter or longer pretty easily ..also it will give you more clearance for your tube if your mount is a GEM when near the meridian

Norm

Bingo! I have had my observatory for over 8 years and I have modified the pier twice in that time. The first modification was to shorten the pier when I moved from an MI-250 to an AP-900 mount and to beef it up. That is documented here,http://www.mikesastr...quipment/pier2/

Since then I have upgraded to an AP-1200 and I needed to shorten again by almost 6 inches. This time all I had to do was take the metal pier part down and saw off 6", re-drill the holes to mount the top plate and I was done.